1. Field of the Invention
The present invention generally relates to a driver circuit, and more particularly to a driver circuit for reducing power consumption of the display device.
2. Description of Related Art
A liquid crystal display (LCD) includes a timing controller, a display panel, a plurality of gate drivers, and a plurality of source drivers. The display panel includes a plurality of pixel cells arranged in an array, and each pixel cell is coupled to one of a plurality of scan lines and one of a plurality of data lines. The timing controller outputs video data to the source drivers for converting the video data into data driving signals. In addition, the timing controller controls each gate driver to sequentially enable the scan lines, and then controls each source driver to deliver data driving signals to the pixel cells on the enabled scan line via the data liens so as to display a frame.
Generally, the polarities of the data driving signals delivering to the same pixel cell on two successive frames are complementary to prevent the liquid crystal from being polarized by residual charges of the pixel cell. As for the same frame, the data driving signal of a certain pixel cell may have a reversed polarity relative to its adjacent pixel cells to prevent low display quality caused by the crosstalk problem. There are several kinds of polarity inversion, such as frame inversion, column inversion, row inversion, and dot inversion. Taking the dot inversion for example, the adjacent pixel cells on the same data line and the adjacent pixel cells on the same scan line should be driven by the data driving signals with different polarities, e.g. positive polarity and negative polarity. The source driver have to alternatively deliver the data driving signal with the positive polarity and the data driving signal with negative polarity in different scan periods, respectively, for driving the pixel cells on the same data line. Such kind of the source driver causes more power consumption due to high voltage swings of the data driving signals.
On the contrary, the column inversion or the frame inversion is usually adopted for saving power consumption, since the source driver outputs the data driving signals with the same polarity to the pixel cells on the same data line in different scan periods. Nevertheless, the display quality of performing the column inversion or the frame inversion is not good as the dot inversion. As a result, designers have disturbance on trading off between the power consumption and the display quality.
Additionally, when performing polarity inversion, if frequency of switching the positive polarity and the negative polarity is not quick enough, people may perceive flickers on frames easily. Therefore, a Point-to-Point Reduced Swing Differential Signaling (PPRSDS) source driver is provided to increase the operation frequency thereof as desired. The PPRSDS source driver includes a plurality of driving channels controlled by the timing controller, wherein each of the driving channels can receive video data from one of two data paths. In the meantime, each driving channel of the PPRSDS source driver should be set a corresponding data mode for receiving the video data from the corresponding data path.
The number of the source driver used in the LCD increases with the increases of the resolution of the display panel. The source drivers may be disposed at different sides of the display panel, e.g. upper side and lower side, due to the limitation of panel layout space. As a result, the driving channels of different source drivers at two ends of the same data line may have different data modes, or namely have unmatched data modes, to correctly receive video data. Therefore, there should be a correlative scheme to ensure that the driving channels of the source driver can receive the corresponding video data.